Lambda Functions

It's best to start off with some examples:

Example 1:

my_list = range(26)
print(filter(lambda x: x % 2 == 0, my_list))

Example 2:

g = lambda x,y: x>y
print g(1,2)
print g(2,1)

As you can tell, lambdas appear to be shortened functions; specifically one lined functions. And while this is true to an extent... that is not their purpose. Nor are Lambdas like C/C++ inline statements... used for performance reasons.

Lambdas, in short, are anonymous functions. Functions without a name. They are generally passed as arguments to higher-order functions as well as a variety of other uses. Below are some of the features of a Lambda

Lambda Features:

• Lambda forms can take any number of arguments

• Return only one value in the form of an expression

• They cannot contain commands or multiple expressions

• It cannot be a direct call to print because lambda requires an expression

• Lambda functions have their own namespace

Due to the fact that they have their own local namespace... Lambdas cannot access variables other than those in their parameters list and globals.

Breakdown of a Lambda

#Define a regular function
def reg_function(x):
    return x**2

# Make it one line
def reg_function(x): return x**2

# Turn it into a lambda
new_stuff = lambda x: x**2

Lab 4A: Calculator

Create a fully functional calculator using BOTH functions and lambdas. Create a user menu as well as a "screen" where the numbers and operations take place. The calculator needs to have the following functionality:

• Addition
• Subtraction
• Division
• Multiplication
• Power

Additional Features:

• More than two numbers
• Continuous operations (5 + 5 + 2 - 1 / 2 for example)
• Additional operations
• etc